Outdoors Grabbit? You bet - rare combination of lightness, decent brightness and USB charging makes this a brilliant pack and forget option. The floody beam gives enough brightness for walking, camping and non-technical running and can be dimmed steplessly for optimal ambient lighting too. Burn time is two hours at the 150-lumen max output and around three hours of varied use and it struggles at full pelt on technical terrain, but given its size and weight, all-round performance is stellar, especially on days when you wouldn't even pack a heavier headtorch. Great back-up light.

Full Review Below

Black Diamond Iota Headtorch - Performance

We've rapidly become huge fans of the Iota. It's a tiny, compact headtorch that's actually bright enough to be worth carrying in the first place. To put it in perspective, at 54 grammes it's around 30 grammes lighter than the 2016 version of Petzl's iconic Tikka, but manages to be USB rechargeable as well.

That makes it super convenient - no scrabbling around for AAA batteries when you're packing for the weekend just plug in and charge. You don't lose out on sophistication either. The Icon has a neat little three-level power gauge that comes on for 3 seconds after switching on and in use, features Black Diamond's PowerTap stepless dimming, which allows you to seamlessly adjust the output to suit your needs.

Black Diamond Iota Headtorch front side view

Lukasz Warzecha

Simple elasticated headband is comfortable and easy to use. The head-unit pivots reliably to your angle of choice and stays there even over rough ground. And the top-mounted switch is fine with winter gloves.

Power And Burn

The 150-lumen maximum output doesn't compete with more powerful torches we've tested, but the floody beam is more than bright enough for general walking use and running on less technical terrain.

At maximum output BD says it'll manage two hours and with more varied use, around three hours - maximum burn is claimed to be 20 hours by the way. We found that about right, but bear in mind all torches tend to lose burn time in colder conditions. That makes it ideal as a 'get you home' light for dusk-time missions and as a 'just-in-case' stand-by stashed in the lid of your pack.

It'll also happily manage campsite duties if you ramp it down to delay the dimming of the light... Of course if you do run out of power you can't simply slot in a fresh battery, but we found it easy enough to charge up using a power bank back-up. It won't light while charging though.

Black Diamond Iota Headtorch studio shot

Lukasz Warzecha

Black Diamond Iota Headtorch - Verdict

We've seen the Iota criticised for short burn-times and relatively modest output, but that's missing the point. It's a brilliant second head-torch for outings when you might just need a serviceable light to get you home safely, and space and weight matter.

You can slip it in a pocket or a bum-bag and it's light enough that you barely know it's there. Where it scores over other lightweights is that it's also bright enough to be useful, has a fully adjustable output and charges up from a USB socket in around three hours.

Little touches like the lock-out - just hold the power button down for around four seconds to avoid accidental ignition - and the stepless dimming are the icing on the cake.